Two million teenagers in the United States have sniffed or inhaled a substance such as glue, gasoline, solvents, nitrous oxide, or spray paint to get high. Most young people who engage in this dangerous practice give it up over time, but a minority go on to develop serious problems with inhalants, greatly increasing the chances of permanently damaging their health. In a recent study of survey data, NIDA-funded investigators showed that the youths who progress to regular inhalant abuse and dependence tend also to exhibit a set of other problematic behavioral characteristics.

Dr. Li-Tzy Wu of RTI International in North Carolina and her colleagues, Dr. Daniel Pilowsky at Columbia University in New York City and Dr. William Schlenger at RTI International, analyzed data on 36,859 teens aged 12 to 17 drawn from the combined 2000 and 2001 National Household Surveys on Drug Abuse (NHSDA). They found that adolescents with inhalant abuse diagnoses were likelier than others to have already abused these drugs by age 13 or 14 and to have abused two or more other drugs besides inhalants in the year prior to being surveyed. These youths also were more likely to have serious coexisting problems, such as a history of delinquent acts—for example, stealing, fighting, and carrying a handgun—and to have used mental health services for nondrug issues (see "Adolescent Inhalant Abuse More Likely in the Presence of Specific Behaviors"). Based on the characteristics they identified, the investigators concluded that adolescents with inhalant abuse disorder or dependence make up a subgroup of highly troubled youths with multiple vulnerabilities. The study did not identify any cause of this vulnerability, but it did paint a picture of youths with many problems.

Adolescent Inhalant Abuse More Likely in the
Presence of Specific Behaviors

Characteristic

Probability of Abuse Disorder*, times more likely

Probability of Dependence Disorder*, times more likely

Age of first inhalant abuse
13-14 v. 15-17

Not more likely

5

Abuse of three inhalants
v. one

4

3

Weekly inhalant abuse v.
less-frequent use

2

4

Past-year delinquent behaviors three v. none

6

3

Past-year abuse/dependence
of illegal drugs two other drugs v. no abuse three other drugs v. no abuse

5

18

12

24

Past-year use of mental health services for nondrug problems v. no service use

2

4

*As defined by the DSM-IV. Abuse disorder is defined as having one or more drug-related problems in the past year, but not meeting the criteria for dependence; dependence disorder is defined as having three or more drug-related problems in the past year.

Particular characteristics are associated with increased likelihood of
inhalant abuse or dependence among young people who abused an
inhalant once in the past year.

"Although the kids who abuse inhalants seem to have other drug abuse, emotional difficulties, and delinquent behaviors, the cross-sectional design of this study means we can't say which came first—inhalant abuse or other problems. Longitudinal research is needed to identify the sequence and nature of behaviors involved in inhalant use disorders," says Dr. Pilowsky.

Overall, the NHSDA data showed that 9 percent of teenagers had abused an inhalant at least once. Inhalant abuse was most common among adolescents who were older than 14, residents of rural areas, or of Native American or multiethnic heritage. Girls were just as likely as boys to have abused inhalants—an unusual pattern with drugs of abuse. "Boys tend to get involved with drugs more than girls. Inhalants seem to be a notable exception," says Dr. Lynda Erinoff of NIDA's Division of Epidemiology, Services and Prevention Research. Boys' overall higher likelihood of involvement with drugs may relate to their more frequent exposure to situations in which these substances are available. Inhalants may be an exception because boys and girls have the same level of access to them—many inhalants are found in common household products, such as nail polish remover, cleaning fluids, toxic marking pens, and lighter fluid.

A relatively small number (0.2 percent) of the survey respondents met the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria for inhalant abuse disorder or dependence. Among youths who had abused inhalants in the past year, 6 percent had abuse disorder and 4 percent were dependent. Many (60 percent) past-year inhalant abusers said they abused more than one substance. It was not uncommon for these youths to report abusing inhalants weekly or more often (20 percent) and for more than a year (35 percent).

Understanding the prevalence of inhalant abuse and identifying characteristics of young people with serious inhalant problems are initial steps in the design of prevention and treatment interventions. Teenagers who abuse inhalants may do so under the mistaken assumption that common household products are not addictive or harmful. Less than half of eighth-graders perceived trying inhalants once or twice as a "great risk," according to the 2004 Monitoring the Future (MTF) survey, an annual NIDA-funded study of drug abuse among 8th-, 10th-, and 12th-graders. In fact, inhalants act on the same brain areas and neurotransmitter systems as cocaine, amphetamines, and other addictive drugs (see "Dopamine Enhancement Underlies a Toluene Behavioral Effect"). Along with the risk of addiction, inhaling these chemicals occasionally can cause deaths from heart failure or suffocation. Regular abuse can cause damage to the brain, liver, kidneys, lungs, and heart.

Inhalant abuse among high school students peaked in 1995, when, for example, almost 22 percent of eighth-graders sampled reported having abused an inhalant. That year, the Partnership for a Drug-Free America conducted an anti-inhalant media campaign highlighting the health consequences of inhalant abuse. Getting information about the dangers of inhalant abuse and signs of addiction to parents, teachers, and teenagers appears to have had positive results: Abuse of these substances decreased substantially among all three grades after 1995, according to the MTF survey. Trend analysis indicates that the percentage of teens who have abused inhalants fell from 15.6 to 14.2 percent between 2001 and 2004.

However, the most recent MTF survey suggests that inhalant abuse may be rebounding. In contrast to the decline in overall drug abuse among high school students, past-year inhalant abuse increased from 2003 to 2004 for all students surveyed. Lifetime inhalant abuse among eighth-graders increased from 15.8 to 17.3 percent last year. "Although this is not a major change, we should watch these numbers carefully over the next couple of years," says Dr. Erinoff. MTF investigators point out that the number of 8th- and 10th-graders who believe inhalant abuse is dangerous has declined in the past 3 years, which may suggest a need to highlight the dangers in media messages and prevention programs.

Source:

Wu, L.T.; Pilowsky, D.J.; and Schlenger, W.E. Inhalant abuse and dependence among adolescents in the United States. Journal of the American Academy of Child and Adolescent Psychiatry 43(10):1206-1214, 2004. [Abstract]